This application claims the benefit of Japanese Patent Applications No. 11-353730 filed Dec. 13, 1999 and No. 11-353731 filed Dec. 13, 1999, in the Japanese Patent Office, the disclosures of which are hereby incorporated by reference.
1. Field of the Invention
The present invention generally relates to multiprocessor systems and data transfer methods, and more particularly to a multiprocessor system in which a plurality of system modules each having a plurality of processors are connected, and to a data transfer method which is employed in such a multiprocessor system.
2. Description of the Related Art
In the conventional multiprocessor system, a plurality of processors are connected via a bus. However, as the number of processor becomes large and the scale of the multiprocessor system becomes large, contentions are frequently generated on the bus. For this reason, it is becoming more difficult to carry out the data transfer at a high speed with a high efficiency.
Accordingly, when the number of processors becomes extremely large in the conventional multiprocessor system, it is desired to carry out the data transfer at a high speed with a high efficiency. Consequently, although the number of processors is originally increased in order to improve the performance of the multiprocessor system, it is also desired to greatly improve the performance from the point of view of the data transfer among the processors.
Accordingly, it is a general object of the present invention to provide a novel and useful multiprocessor system and data transfer method, in which the problems described above are eliminated.
Another and more specific object of the present invention is to provide a multiprocessor system and a data transfer method, which can carry out a data transfer at a high speed with a high efficiency, even if the number of processors becomes large and the scale of the multiprocessor system becomes large.
Still another object of the present invention is to provide a multiprocessor system comprising a plurality of system modules each having a plurality of processors, a transfer controller and a first crossbar, a crossbar module including a second crossbar, a control bus coupling the transfer controller of each of the system modules to the crossbar module, and a data bus coupling the first crossbar of each of the system modules to the crossbar module, wherein, within an arbitrary one of the system modules, the first crossbar outputs a data packet to the data bus in response to a command signal from the transfer controller after the transfer controller outputs a control information packet to the control bus. According to the multiprocessor system of the present invention, it is possible to carry out a data transfer at a high speed with a high efficiency, even if the number of processors becomes large and the scale of the multiprocessor system becomes large.
A further object of the present invention is to provide a data transfer method for a multiprocessor system in which a plurality of system modules each including a plurality of processors, a transfer controller and a first crossbar are coupled to a crossbar module including a second crossbar, via a control bus and a data bus, comprising the operation of, within an arbitrary one of the system modules, outputting a data packet to the data bus from the first crossbar in response to a command signal from the transfer controller after the transfer controller outputs a control information packet to the control bus. According to the data transfer method of the present invention, it is possible to carry out a data transfer at a high speed with a high efficiency, even if the number of processors becomes large and the scale of the multiprocessor system becomes large.
Another object of the present invention is to provide a multiprocessor system comprising a plurality of system modules each including a plurality of processors, a transfer controller and a first crossbar, and a crossbar module including a second crossbar which couples the plurality of system modules, wherein, when making a transfer within an arbitrary one of the plurality of system modules, the transfer controller transfers a control information packet therewithin without passing the second crossbar. According to the multiprocessor system of the present invention, it is possible to carry out a data transfer at a high speed with a high efficiency, even if the number of processors becomes large and the scale of the multiprocessor system becomes large.
Still another object of the present invention is to provide a data transfer method for a multiprocessor system in which a plurality of system modules each including a plurality of processors, a transfer controller and a first crossbar are coupled to a crossbar module including a second crossbar, comprising the operation of, within an arbitrary one of the system modules, transferring a control information packet and a data packet within the arbitrary system module without passing the second crossbar. According to the data transfer method of the present invention, it is possible to carry out a data transfer at a high speed with a high efficiency, even if the number of processors becomes large and the scale of the multiprocessor system becomes large.